The invention concerns a device for deflecting optical beams, comprising a piezo plate having piezoelectric regions and comprising piezo electrodes, disposed on surfaces, to drive said piezo plate.
A device of this kind is known from the article xe2x80x9cPiezoelectric bimorph optical beam scanners: analysis and construction,xe2x80x9d by J. Kelly Lee, published in Applied Optics, Vol. 18. No. 4, pp. 454-459. In this prior device, a mirror is mounted on a piezo plate. When the device is driven by piezo electrodes with a control voltage in the medium voltage range, the mirror moves as a result of the flexure induced in the piezo plate. A disadvantage of this device is the comparatively high mass that must be moved, which is an obstacle to rapid drive.
The object of the invention is to provide a device of the first-cited type that is distinguished by rapid drivability and distortion-free deflection.
This object is achieved according to the invention in a device of the first-cited type by the fact that the piezo plate is free of piezo electrodes in at least an end portion.
Because there are no piezo electrodes in an end portion of the piezo plate, no flexure is induced in that end portion, which instead remains substantially planar. If the electrode-free end portion is dimensioned to be relatively large compared to the dimensions of the beams incident thereon, reflection or transmission by the end portion will result in little or no distortion of the wave fronts and thus of the beam characteristic, especially the divergence.